Prevalence and Antibiotic Resistance Pattern of Staphylococcus Aureus Strains Isolated from Food Stuff

Staphylococcus aureus is considered to be one of the leading causes of food-borne illnesses. Foodstuff contamination may occur directly from contaminated food-producing animals or may result from poor hygiene during food production processes, or the retail and storage of foods, since humans may carry the microorganism. The number of S.aureus strains that exhibits antimicrobial-resistance properties has increased, together with the potential risk of transmitting the same properties to the human microflora via food or inducing infections hard to be treated. The aim of this study was to evaluate the occurrence of S.aureus in various food samples and determination of antibiotic resistance pattern in this isolates. A total of 1047 food samples were analysed from July 2006 to December 2007. To determine the presence of S.aureus, the samples were analysed according to the guidelines of Iran standard instructions (No.1194). S.aureus isolates were tested for susceptibility to a panel of 11 antimicrobics using the agar disc diffusion method on Muller-Hinton agar. Of 1047 samples analysed 100 (9.5%) were contaminated with S.aureus. Among these contaminated samples, 31% showed antimicrobial resistance properties to at least one of the antibiotic tested and 15 antibiotypes were determined. According to the observed prevalence of S.aureus strains in food samples and their antibiotic resistance pattern, more attention shonld be paid in foodstuff industry to prevent contamination and transmission of resistant strains.